Close enough, I just did the same calcs. This is what I have....

Close enough, I just did the same calcs. This is what I have. Firstly in US normal options are taxed when the option is exercised at the difference between the option price and the market value, so this is what get (assuming 15c market price)

(Rounded for easy calc)
7,380,000 @ 5c = 383760
+ Tax @ 37% = 273060
Total Cost = 656820
Mrkt Val = 1107000
Net $450,180

To pay for the T+C he would have to sell 4,378,800 @ 15c = $656,820
He sold 6,610,053 giving a net 2,231,253 sold more than needed to meet the cost, or @.15 = $334,688 cash, converted to $US = $US 217,547

He kept 76,9947 shares and added that to his holding to have a increased position at 8,000,000 shares

So his transactions generated $217,547 in cash and 77k odd extra shares. Given he gets 15% of the sale bonus pool, that probably goes some way to explain the decisions.